D. Rhon1, S. Snodgrass2, J. Cleland3, C. Cook4
1Brooke Army Medical Center, Department of Rehab Medicine, San Antonio, United States, 2University of Newcastle, School of Health Sciences, Callaghan, Australia, 3Tufts University School of Medicine, Department of Physical Therapy, Boston, United States, 4Duke University, Department of Orthopaedics, Durham, United States
Background: One of the strongest predictors of chronic postoperative opioid use is preoperative use.6–10 Preoperative opioid use is also a strong predictor of worse outcomes, higher complication rates, and increased downstream costs. A relationship has also been identified between opioids and several comorbidities, such as sleep disorders, depression, chronic pain, concussion, and metabolic syndromes. However, outside of low back pain,18 the predictive value of prior opioid use for future opioid use has not been investigated in non-surgical and non-cancer pain cohorts.
Purpose: Due to their potentially deleterious effects, minimizing the use of opioids for musculoskeletal pain is a priority for healthcare systems. The objective of this study was to examine the risk of future opioid prescription use based on prior opioid use within a non-surgical cohort with musculoskeletal knee pain. We also examined the risk of pre-existing comorbidities on future opioid use, and the risk of prior opioid use on future comorbidities (sleep, mental health, cardiometabolic disorders).
Methods: Data came from the Military Health System Data Repository for 80,290 consecutive beneficiaries with an initial episode of care for patellofemoral pain from 1 January 2010 through 31 December 2011. Risk calculations were developed with 2x2 tables based on pre and post opioid utilization and comorbidity diagnosis. Risk ratios, relative and absolute risk increases, and numbers needed to harm were calculated, all with 95% confidence intervals.
Results: Prior opioid use resulted in a risk ratio of 18.0 (95CI 17.1, 19.0) and an absolute risk increase of 61.6% for future opioid use (numbers needed to harm=2). The presence of most comorbidities had a significant relative risk for future opioid use (range 1.2-1.5), but the absolute risk increase was trivial (range 0.7%-2.2%). The relative risk for a chronic pain diagnosis, traumatic brain injury/concussion, insomnia, depression, and PTSD were all significantly higher in those with prior opioid use (1.3-1.6), but absolute risk increase was minimal (1.1%-6.5%).
Conclusion(s): Prior opioid use was a very strong risk factor for future prior opioid use (RR 18.1), with an absolute risk increase of 61.6%. While this risk factor has been well established in surgical patients with musculoskeletal pain,6–9,33,34 much less is known about the risk in non-surgical patients. In addition, even in surgical cohorts, ARI is seldom reported, making it challenging to interpret the clinical relevance of the risk ratios reported. This investigation in a large cohort of patients within a large health system increases our understanding of the influence that prior opioid use has on future opioid use, and in non-surgical patients seeking care for musculoskeletal pain.
Implications: Based on the findings from this study, clinicians should consider prior opioid use patterns when initially managing patients with patellofemoral pain. While prior opioid utilization is not something that can be modified at the point of care, it can provide valuable information that can potentially influence future care decisions.
Funding, acknowledgements: no funding
Keywords: opioid risk, health services research, patellofemoral pain
Topic: Pain & pain management
Did this work require ethics approval? Yes
Institution: Brooke Army Medical Center
Committee: Central Regional Health Command IRB
Ethics number: C.2016.048n
All authors, affiliations and abstracts have been published as submitted.
